Chris Tate
3cafa64fe7
concat read a receiver's length before appending it, flatMap called its callback without thisArg, and with, toReversed, toSorted and toSpliced checked indexes with HasProperty, which a proxy's has trap or a getter observes. Writes to a string receiver were discarded, though a String wrapper's indexes below its length and its length are read-only. - concat appends a receiver that is not an array as its first element without reading `length`; the array dispatch's concat spreads the arguments. - flatMap calls the callback with thisArg as `this`. - with, toReversed, toSorted and toSpliced read every index with Get alone and define it on the result, so a missing index becomes undefined. toReversed reads from the last index down, with never reads the index it replaces, and toSpliced without arguments returns a copy. - On a string receiver, a write to an index below the string's length or to `length` throws "Cannot assign to read only property '<key>' of object '[object String]'", and deleting such an index throws "Cannot delete property '<index>' of [object String]", as in Node. Writes to number, boolean, bigint and symbol receivers are still discarded with their wrapper. - fill, copyWithin and reverse return their receiver, which for a primitive is its wrapper object, and concat's result starts with it. A compiled program has no wrapper objects, so these calls on a primitive throw the "not supported yet" Error. - An array receiver held as an untyped value ran these methods through scr_dyn_array_proto_call, which implements none of them, and threw "not supported yet". It now runs them through the array dispatch.
scriptc
scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses the types checked by the TypeScript compiler to generate machine code, and the output runs without Node.js installed. npm packages your program imports compile along with it. Code scriptc can't compile is reported at build time with a diagnostic and, where available, a rewrite hint.
scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. Run scriptc coverage on an existing program to see how much of it compiles, and see the limitations and Node.js compatibility reference for details.
Installation
Install with Node.js 24 or later and npm:
$ npm install -g scriptc
The installed compiler runs natively on macOS, Linux, and Windows. Node.js is needed only to install it and to run WASI modules with scriptc run. Standalone compiler archives are also available from GitHub Releases.
Building executables requires a linker and the platform SDK or sysroot. See the quickstart for prerequisites and platform support for host requirements, cross-compilation, and WebAssembly.
Build a program
Create hello.ts:
const who = process.argv.length > 2 ? process.argv[2] : "world";
console.log(`hello, ${who}`);
scriptc run compiles the file and runs the result:
$ scriptc run hello.ts
hello, world
scriptc build writes an executable:
$ scriptc build hello.ts -o hello >/dev/null
$ ./hello scriptc
hello, scriptc
These examples use POSIX shell syntax. On Windows, build hello.exe and run it with .\hello.exe.
Use scriptc coverage hello.ts to check what compiles before you build. See coverage reports for details.
Use Node APIs
Supported Node APIs compile to the native runtime. For example, server.ts:
import { createServer } from "node:http";
const server = createServer((req, res) => {
res.setHeader("content-type", "application/json");
res.end(JSON.stringify({ path: req.url }));
});
server.listen(8080, () => {
console.log("listening on http://localhost:8080");
});
$ scriptc build server.ts -o server >/dev/null
$ ./server
listening on http://localhost:8080
Use npm packages
npm packages compile into the executable with your code, so it doesn't read node_modules at runtime.
Create cli.ts:
import pc from "picocolors";
console.log(pc.green("hello from scriptc"));
$ npm install picocolors
$ scriptc build cli.ts -o cli >/dev/null
$ ./cli
hello from scriptc
Package support is partial. See npm dependencies for which packages compile and how to check them.
Documentation
- Introduction: what scriptc is and what you can build.
- Quickstart: installation and your first executable.
- Coverage reports: check whether an existing program compiles.
- Platform support: cross-compilation and WebAssembly.
- CLI reference: commands, options, and output formats.
- Native program objects: use compiler output in external builds.
- Native FFI: call C ABI functions from compiled programs.
- WebAssembly modules: build and embed WASI modules.
- Examples: programs and integration examples in this repository.
Contributing
See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.